Re: Same HD, same settings, different geometry

Luca Montecchiani (m.luca@iname.com)
Sat, 19 Jun 1999 11:24:46 +0200


"Mike A. Harris" wrote:
>
> On Sat, 19 Jun 1999, Luca Montecchiani wrote:
>
> >Hi all,
> >in my Pc I've two IDE, hda ( primary on 1ide ) and hdc ( primary on 2ide ) the
> >bios settings on the motherboard is auto/LBA for all 4 ide channels.
> >
> >The facts on kernel 2.x.x
> >-------------------------
> >When linux boots hda show the "bios" geometry (LBA), and hdc show the physical
> >geometry. This worry me, but everything work fine and /proc/ide/hd*/geometry
> >is my friend. Seeing those difference, especially in my office machine where
> >hda and hdc are the same models make me unhappy :(
> >I started to look in the code ( 2.2.10 ) to understand why...
> >In short only hd's on the primary ide interface will showed with their bios/cmos
> >geometry.
>
> To avoid this problem, I religiously partition fresh factory
> drives on a primary master or primary slave *always*. You only
> need to make one partition. Then the drive can be moved to the
> secondary without worry.

So it's impossible to fdisk a "fresh factory hd" on the secondary ide ??
Hmm let me see...

ide.c
* To do, in likely order of completion:
* - modify kernel to obtain BIOS geometry for drives on 2nd/3rd/4th i/f
*/

ide-probe.c
* The only "perfect" way to handle this would be to modify the setup.[cS] code
* to do BIOS calls Int13h/Fn08h and Int13h/Fn48h to get all of the drive info
* for us during initialization. I have the necessary docs -- any takers? -ml
*/

-----------------------------------------------------------------------
Is there any plan to improve/cleanup the IDE-Geometry stuff in 2.3.x ??
-----------------------------------------------------------------------

> If you don't have a free primary, and cannot remove one of the
> primary drives to do this, you can either shut the machine down
> and boot off a boot floppy containing fdisk, after removing a
> primary drive, and replacing it with the one you wish to
> partition, or you can use a different computer to do the
> partitioning.
>
> It is a good workaround.

Sure but we can "do it better" ;) It's funny to think about a
fdisker.mydomain.com on my network :P

Anyway I need to know if my upatch will break something.
I don't think because it's essentially _cosmetics_, but with "hdX=nocmosgeom"
(*)
we use the same way to retrieve hda and hdc geometry :).

The problem I see is only in "installation like" situations
when hda is a "fresh hd" that we want to fdisk, simply don't use
hdX=nocmosgeom (*).

thanks, luca

(*) where hdX=hda or hdb
_______________________________________________________________
Aiem...: Luca Montecchiani W.W.W.: http://i.am/m.luca
E-mail.: m.luca@iname.com Kernel: 2.2
I.R.C..: defrag (#linux-it) I.C.Q.: 17655604
PGP5.0i: available on my home page Lime98: io c'ero ;)
_______________________________________________________________

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